Statement of the Technical Field
The present invention relates generally to magnetic core antennas. More particularly, the present invention relates to magnetic core antennas for use in a variety of systems such as an Electronic Article Surveillance (“EAS”) detection system or a Radio Frequency Identification (“RFID”) system.
Description of the Related Art
EAS and RFID detection systems are typically used to protect and track assets. In an EAS detection system, an interrogation zone is established at the perimeter of a protected area. For example, the interrogation zone is in the vicinity of an exit from a facility such as a retail store. The interrogation zone is established by an interrogation device positioned adjacent to the desired interrogation zone. The interrogation device comprises an antenna which transmits an electromagnetic interrogation signal into an interrogation zone so as to create an electromagnetic field of sufficient strength and uniformity therein.
EAS markers (attached to each asset to be protected) respond in some known electromagnetic manner to the electromagnetic interrogation signal. When an asset is properly purchased or otherwise authorized for removal from the protected area, the EAS marker is either removed therefrom or deactivated such that the presence of the asset within the interrogation zone does not cause issuance of an alarm. In contrast, if the EAS marker is not removed or deactivated, then electromagnetic interrogation signal causes a response from the EAS marker when present within the interrogation zone. A detection antenna detects the EAS marker's response indicating that an active EAS marker is presently within the interrogation zone. An associated controller provides an indication of this condition, such as issuing an audio alarm for preventing an unauthorized removal of the asset from the protected area. In this regard, the alarm can be the basis for initiating one or more appropriate responses depending upon the nature of the facility.
An RFID detection system utilizes an RFID marker to track assets for various purposes, such as taking inventory. The RFID marker stores data associated with the asset. An RFID reader scans the RFID markers by transmitting an RFID interrogation signal at a known frequency. RFID markers respond to the RFID interrogation signal with RFID response signals including asset-related data associated with the assets being protected thereby. The RFID reader detects the response signals and decodes the asset-related data.